How can i make more realistic lighting/materials
You'll need something to be reflected.

If your world is just black, there is nothing to be reflected by your material.

As suggested by Gonzou, I'd try a HDR / IBL image.
Alot of those Images can be found here:
http://www.hdrlabs.com/sibl/archive.html

Those will lighty your scene / object and so there is something to be reflected.



Speaking of materials i'd suggest this tutorial:
https://www.youtube.com/watch?v=rzXNZkEoTAk

It's quite helpful to get a bit more interesting looking materials.